package com.javajun.custom;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class HttpConnectionUtil {
    /**
     * 从网络Url中下载文件
     * @param urlStr
     * @param fileName
     * @param savePath
     * @throws IOException
     */
    public static void  downLoadFromUrl(String urlStr,String fileName,String savePath) throws IOException{
        URL url = new URL(urlStr);  
        HttpURLConnection conn = (HttpURLConnection)url.openConnection();  
                //设置超时间为3秒
        conn.setConnectTimeout(3*1000);
        //防止屏蔽程序抓取而返回403错误
        conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");
 
        String filePathUrl = conn.getURL().getFile();
        String fileFullName = filePathUrl.substring(filePathUrl.lastIndexOf(File.separatorChar) + 1);
        System.out.println("文件名："+fileFullName);
        //得到输入流
        InputStream inputStream = conn.getInputStream();  
        //获取自己数组
        byte[] getData = readInputStream(inputStream);    
 
        //文件保存位置
        File saveDir = new File(savePath);
        if(!saveDir.exists()){
            saveDir.mkdir();
        }
        File file = new File(saveDir+File.separator+fileName);    
        FileOutputStream fos = new FileOutputStream(file);     
        fos.write(getData); 
        if(fos!=null){
            fos.close();  
        }
        if(inputStream!=null){
            inputStream.close();
        }
 
 
        System.out.println("info:"+url+" download success"); 
 
    }
 
 
 
    /**
     * 从输入流中获取字节数组
     * @param inputStream
     * @return
     * @throws IOException
     */
    public static  byte[] readInputStream(InputStream inputStream) throws IOException {  
        byte[] buffer = new byte[1024];  
        int len = 0;  
        ByteArrayOutputStream bos = new ByteArrayOutputStream();  
        while((len = inputStream.read(buffer)) != -1) {  
            bos.write(buffer, 0, len);  
        }  
        bos.close();  
        return bos.toByteArray();  
    }  
 
    public void aaaa() {
        try{
            downLoadFromUrl("https://img3.doubanio.com/view/subject/s/public/s29785016.jpg",
                    "百度.jpg","d:/aaa/");
            System.out.println("1231546154dasd");
        }catch (Exception e) {
            // TODO: handle exception
        }
    }

}
